/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.chess.annotation.demo;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.widget.RelativeLayout;

public class ZoomRelativeLayoutV2 extends RelativeLayout {
	private static final int INVALID_POINTER_ID = -1;
	protected State mode = State.NONE;
	private float mPosX;
	private float mPosY;

	private float mLastTouchX;
	private float mLastTouchY;
	private int mActivePointerId = INVALID_POINTER_ID;

	private ScaleGestureDetector mScaleDetector;
	private float mScaleFactor = 1.0f;
	private float miniScaleFactor = 1.0f;

	public ZoomRelativeLayoutV2(Context context) {
		this(context, null, 0);
	}

	public ZoomRelativeLayoutV2(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public ZoomRelativeLayoutV2(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
	}

	@Override
	public boolean onTouchEvent(MotionEvent ev) {
		// Let the ScaleGestureDetector inspect all events.
		mScaleDetector.onTouchEvent(ev);

		final int action = ev.getAction();
		switch (action & MotionEvent.ACTION_MASK) {
		case MotionEvent.ACTION_DOWN: {
			final float x = ev.getX();
			final float y = ev.getY();

			mLastTouchX = x;
			mLastTouchY = y;
			mActivePointerId = ev.getPointerId(0);
			break;
		}

		case MotionEvent.ACTION_MOVE: {
			final int pointerIndex = ev.findPointerIndex(mActivePointerId);
			final float x = ev.getX(pointerIndex);
			final float y = ev.getY(pointerIndex);

			// Only move if the ScaleGestureDetector isn't processing a gesture.
			if (!mScaleDetector.isInProgress()) {
				final float dx = x - mLastTouchX;
				final float dy = y - mLastTouchY;

				mPosX += dx;
				mPosY += dy;
				mode = State.DRAG;
				updateView();
			}

			 mLastTouchX = x;
			 mLastTouchY = y;

			break;
		}

		case MotionEvent.ACTION_UP: {
			mActivePointerId = INVALID_POINTER_ID;
			mode = State.NONE;
			break;
		}

		case MotionEvent.ACTION_CANCEL: {
			mActivePointerId = INVALID_POINTER_ID;
			break;
		}

		case MotionEvent.ACTION_POINTER_UP: {
			final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
			final int pointerId = ev.getPointerId(pointerIndex);
			if (pointerId == mActivePointerId) {
				// This was our active pointer going up. Choose a new
				// active pointer and adjust accordingly.
				final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
				mLastTouchX = ev.getX(newPointerIndex);
				mLastTouchY = ev.getY(newPointerIndex);
				mActivePointerId = ev.getPointerId(newPointerIndex);
			}
			break;
		}
		}

		return true;
	}

	public void updateView() {
		// android.util.Log.d("temp", "scale:" + mScaleFactor + ", dx:" + mPosX + ",dy:" + mPosY);
		if (mode == State.ZOOM) {
			this.setScaleX(mScaleFactor);
			this.setScaleY(mScaleFactor);
		} else {
			this.setTranslationX(mPosX);
			this.setTranslationY(mPosY);
		}

	}

	private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
		@Override
		public boolean onScale(ScaleGestureDetector detector) {
			if (detector.getScaleFactor() > 1.0f) {
				android.util.Log.d("temp", "zoom out");
			} else {
				android.util.Log.d("temp", "zoom in");
			}
			mScaleFactor *= detector.getScaleFactor();
			// Don't let the object get too small or too large.
			mScaleFactor = Math.max(miniScaleFactor, Math.min(mScaleFactor, 5.0f));
			mode = State.ZOOM;
			updateView();
			return true;
		}
	}
}
